Bucculentum, Schweitzer & Feldmann, 2009

Krzemińska, Ewa, Starzyk, Natalia, Fraaije, René H. B., Schweigert, Günter & Lukeneder, Alexander, 2021, Jurassic brachyurans of the genus Bucculentum, Zootaxa 5032 (3), pp. 395-410 : 400-401

Bucculentum cf. B. bucculentum

Fig. 4

Material examined. Specimen SMNS 66654 : Gundershofen-Springen , source of Schmiech river, southern Germany (N 48 o 38’, E 9 o 59’); age: Late Kimmeridgian, Pseudomutabilis Zone (according to Ziegler 1959) .

Description. The specimen is characterized by two unique features: the shape of the suborbital spine and mesobranchial regions. The suborbital spine ( Fig. 4A, B ) is very broad, flat, and curved. The mesobranchial regions are very small and of semicircular outline, while in other specimens of the genus they are larger and triangular. Other features are concordant with those of B. bucculentum .

Remarks. The specimen is symmetrical and well preserved, therefore, the carapace seems to present genuine characters. The suborbital spine such as in this specimen is not encountered in any other species of Bucculentum . However, it cannot be excluded that its shape results from taphonomic conditions; the second spine is not preserved, therefore it is not possible to compare their symmetry. Since we are not sure of the genuine shape, we refrain from description of a new species. On the other hand, if the specimen represents really B. bucculentum , the range of this species would be extended to the Late Kimmeridgian ( Fig. 11 ).

Figures

FIGURE 4. Bucculentum cf. bucculentum, specimen SMNS 66654, Gundershofen-Springen, Upper Kimmeridgian. Bars 1 mm.

FIGURE 11. Age and occurrence of four species of Bucculentum (symbols as in Fig. 10. Source of the map: https://vemaps. com/europe-continent/eu-c-0).